Nissan Altima L32. Manual - part 545

P0420, P0430 THREE WAY CATALYST FUNCTION

EC-1301

< COMPONENT DIAGNOSIS >

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11. Rev engine between 2,000 and 3,000 rpm and hold it for 3 consecutive minutes then release the acceler-

ator pedal completely.

12. Check the indication of “CATALYST”.
Which is displayed on CONSULT-III screen?

CMPLT >> GO TO 6.

INCMP >> GO TO 4.

4.

PERFORM DTC CONFIRMATION PROCEDURE-II

1. Wait 5 seconds at idle.

2. Rev engine between 2,000 and 3,000 rpm and maintain it until “INCMP” of “CATALYST” changes to

“CMPLT” (It will take approximately 5 minutes).

Does the indication change to “CMPLT”?

YES

>> GO TO 6.

NO

>> GO TO 5.

5.

PERFORM DTC CONFIRMATION PROCEDURE AGAIN

1. Stop engine and cool it down to less than 70

°C (158°F).

2. Perform DTC CONFIRMATION PROCEDURE again.

>> GO TO 3.

6.

PERFORM DTC CONFIRMATION PROCEDURE-III

Check 1st trip DTC.
Is 1st trip DTC detected?

YES

>> Go to 

EC-1302, "Diagnosis Procedure"

.

NO

>> INSPECTION END

7.

PERFORM COMPONENT FUNCTION CHECK

Perform component function check. Refer to 

EC-1301, "Component Function Check"

.

NOTE:

Use component function check to check the overall function of the three way catalyst (manifold). During this

check, a 1st trip DTC might not be confirmed.
Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Go to 

EC-1302, "Diagnosis Procedure"

.

Component Function Check

INFOID:0000000004362149

1.

PERFORM COMPONENT FUNCTION CHECK

Without CONSULT-III

1. Start engine and warm it up to the normal operating temperature.

2. Turn ignition switch OFF and wait at least 10 seconds.

3. Turn ignition switch ON.

4. Turn ignition switch OFF and wait at least 10 seconds.

5. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.

6. Let engine idle for 1 minute.

7. Open engine hood.

8. Check the voltage between ECM harness connector terminals

under the following conditions.

JMBIA1865ZZ

EC-1302

< COMPONENT DIAGNOSIS >

[VQ35DE]

P0420, P0430 THREE WAY CATALYST FUNCTION

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Go to 

EC-1302, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000004362150

1.

CHECK EXHAUST SYSTEM

Visually check exhaust tubes and muffler for dents.
Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Repair or replace malfunctioning part.

2.

CHECK EXHAUST GAS LEAKAGE

1. Start engine and run it at idle.

2. Listen for an exhaust gas leakage before the three way catalyst (manifold).

Is exhaust gas leakage detected?

YES

>> Repair or replace malfunctioning part.

NO

>> GO TO 3.

3.

CHECK INTAKE AIR LEAKAGE

Listen for an intake air leakage after the mass air flow sensor.
Is intake air leakage detected?

YES

>> Repair or replace malfunctioning part.

NO

>> GO TO 4.

4.

CHECK IGNITION TIMING

Check idle speed and ignition timing.

For procedure, refer to 

EC-1048, "BASIC INSPECTION : Special Repair Requirement"

.

For specification, refer to 

EC-1585, "Idle Speed"

 and 

EC-1585, "Ignition Timing"

.

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> Follow the 

EC-1048, "BASIC INSPECTION : Special Repair Requirement"

.

5.

CHECK FUEL INJECTORS

1. Stop engine and then turn ignition switch ON.

DTC

ECM

Condition

Voltage (V)

Connec-

tor

+

–

Terminal

Terminal

P0420

F13

33

[HO2S2 (bank 1) 

signal]

35

(Sensor 
ground)

Keeping engine speed at 2,500 rpm 
constant under no load

The voltage fluctuation cycle takes 
more than 5 seconds.
• 1 cycle: 0.6 - 1.0 

→ 0 - 0.3 → 0.6 - 

1.0

P0430

34

[HO2S2 (bank 2) 

signal]

PBIB1216E

P0420, P0430 THREE WAY CATALYST FUNCTION

EC-1303

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2. Check the voltage between ECM harness connectors.

Is the inspection result normal?

YES

>> GO TO 6.

NO

>> Perform 

EC-1483, "Diagnosis Procedure"

.

6.

CHECK FUNCTION OF IGNITION COIL-I

CAUTION:

Perform the following procedure in a place with no combustible objects and good ventilation.

1. Turn ignition switch OFF.

2. Remove fuel pump fuse in IPDM E/R to release fuel pressure.

NOTE:

Do not use CONSULT-III to release fuel pressure, or fuel pressure applies again during the following pro-

cedure.

3. Start engine.

4. After engine stalls, crank it 2 or 3 times to release all fuel pressure.

5. Turn ignition switch OFF.

6. Remove all ignition coil harness connectors to avoid the electrical discharge from the ignition coils.

7. Remove ignition coil and spark plug of the cylinder to be checked.

8. Crank engine for 5 seconds or more to remove combustion gas in the cylinder.

9. Connect spark plug and harness connector to ignition coil.

10. Fix ignition coil using a rope etc. with gap of 13 - 17 mm (0.52 -

0.66 in) between the edge of the spark plug and grounded metal

portion as shown in the figure.

11. Crank engine for approximately 3 seconds, and check whether

spark is generated between the spark plug and the grounded

metal portion.

CAUTION:

• Never place the spark plug and the ignition coil within 50

cm (19.7 in) each other. Be careful not to get an electrical

shock while checking, because the electrical discharge

voltage becomes 20 kV or more.

• It might damage the ignition coil if the gap of more than 17 mm (0.66 in) is made.

NOTE:

When the gap is less than 13 mm (0.52 in), a spark might be generated even if the coil is malfunc-

tioning.

Is the inspection result normal?

YES

>> GO TO 10.

NO

>> GO TO 7.

7.

CHECK FUNCTION OF IGNITION COIL-II

1. Turn ignition switch OFF.

2. Disconnect spark plug and connect a non-malfunctioning spark plug.

3. Crank engine for approximately 3 seconds, and recheck whether spark is generated between the spark

plug and the grounded metal portion.

ECM

Voltage

+

–

Connector

Terminal

Connector

Terminal

F14

1

E10

112

Battery voltage

3

29

30

31

32

JMBIA1869GB

Spark should be generated.

JMBIA0066GB

EC-1304

< COMPONENT DIAGNOSIS >

[VQ35DE]

P0420, P0430 THREE WAY CATALYST FUNCTION

Is the inspection result normal?

YES

>> GO TO 8.

NO

>> Check ignition coil, power transistor and their circuit. Refer to 

EC-1491, "Diagnosis Procedure"

.

8.

CHECK SPARK PLUG

Check the initial spark plug for fouling, etc.
Is the inspection result normal?

YES

>> Replace spark plug(s) with standard type one(s). For

spark plug type, refer to 

EM-119, "Removal and Installa-

tion"

.

NO

>> Repair or clean spark plug. Then GO TO 9.

9.

CHECK FUNCTION OF IGNITION COIL-III

1. Reconnect the initial spark plugs.

2. Crank engine for approximately 3 seconds, and recheck whether spark is generated between the spark

plug and the grounded portion.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace spark plug(s) with standard type one(s). For spark plug type, refer to 

EM-119, "Removal

and Installation"

.

10.

CHECK FUEL INJECTOR

1. Turn ignition switch OFF.

2. Remove fuel injector assembly.

Refer to 

EM-146, "Removal and Installation"

.

Keep fuel hose and all fuel injectors connected to fuel tube.

3. Disconnect all ignition coil harness connectors.

4. Reconnect all fuel injector harness connectors disconnected.

5. Turn ignition switch ON.

6. Check that fuel does not drip from fuel injector.
Does fuel drip from fuel injector?

YES

>> Replace the fuel injector(s) from which fuel is dripping.

NO

>> GO TO 11.

11.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-42, "Intermittent Incident"

.

Is the inspection result normal?

YES

>> Replace three way catalyst assembly.

NO

>> Repair or Replace harness or connector.

Spark should be generated.

SEF156I

Spark should be generated.